Differential hydraulic cylinders of various design heretofore have been used in environments requiring long extension and retraction distances and in most cases serially arranged cylinder and piston components have been used to accomplish extension and retraction distances or relatively great magnitude. However, conventional multistage cylinders of this type are not adaptable for use in conjunction with loads which are eccentrically applied to the pistons.
In addition, various different forms of cylinders have been specifically designed for use in conjunction with eccentrically disposed loads but most of these cylinders are constructed in a manner which greatly limits extension and retraction distances.
Accordingly, a need exists for an improved form of differential hydraulic cylinder which may be used to support eccentrically disposed loads such as elevator cars or platforms and yet which will be capable of raising and lowering the cars or platforms used in conjunction therewith over relatively great distances.
Examples of various forms of cylinders including some of the general structural and operational features of the instant invention are disclosed U.S. Pat. Nos. 2,634,587, 2,670,811, 3,134,231 and 3,181,436.